KIDD, Michael R.*; KOCHER, Thomas D.; University of New Hampshire; University of New Hampshire: Patterns of Ecological Diversification within Pseudotropheus tropheops, a Subgenus of Rock Dwelling Cichlid from Lake Malawi

The haplochromine cichlids of Africa�s Great Lakes have become a celebrated example of adaptive radiation. Unfortunately, phylogenetic analysis of the Lake Malawi species flock has been confounded by the lack of appropriate morphological characters and an exceptional rate of speciation, which has allowed ancestral molecular polymorphisms to persist within species. To overcome this problem we used Amplified Fragment Length Polymorphism (AFLP) to score more than 7,000 restriction fragment polymorphisms in order to reconstruct the evolutionary relationships among 20 species of the ubiquitous rock dwelling subgenus Pseudotropheus tropheops. Our results suggest that this lineage forms a monophlyletic clade that should be elevated to genus status. This clade has diversified and spread throughout the southeast arm of Lake Malawi without differentiation of either oral or pharyngeal jaw dentition, but has coincided with repeated modification of the oral jaw architecture in order to recapitulate �biter� and �sucker� trophic morphs.